1. Filed of the Invention
The invention relates to processing of scanned images, and particularly, to processing of scanned images of bound documents.
2. Description of the Related Art
When a document with a binding is scanned on a flat bed scanner, the scanned image often appears to have a darker area near the binding. Various factors contribute to the appearance of the darker area. For example, the binding of the document usually “lifts off” of or is separated from the scanner platen. That is, curvature near the binding geometrically distorts the image being scanned. As a result, contents within the distorted image are also geometrically distorted and heavily shaded because the lifted portion of the document reflects less light back into the scanner, thereby causing the lifted portion appear to be darker. The relatively darker portion of the scanned document is often considered to have an unpleasant affect on the scanned image.
Furthermore, when the scanner cover only partially covers the document, or when the cover is completely open, areas adjacent to the image being scanned usually are very dark, and form an unpleasant looking image border around the image. In still other cases, a partial image of an unwanted adjacent page is sometimes inadvertently captured, and again forms another dark edge in the image near the binding. In addition, when the document is scanned, an operator may place unequal pressure on parts of the document. In such a case, the image being scanned may be skewed.